1. Field of the Invention
Apparatuses and methods consistent with the present invention relate to transmitting and receiving graphical data, and more particularly, to transmitting and receiving graphical data in an expandable home theater (XHT) network.
2. Description of the Related Art
Along with the development of digital audio and video (hereinafter, referred to as A/V) processing techniques, various A/V devices, such as digital televisions (TVs), set-top boxes, digital versatile disk (DVD) players, and digital amplifiers, have been installed and used in homes and offices. A user in the home or office can conveniently control these devices using a remote control unit or the like. Accordingly, technology has been developed that connects a plurality of A/V devices to one another for systematization so as to allow the user to conveniently control the A/V devices.
To address this problem, technologies have been researched for mutually connecting a plurality of A/V devices, and combining the devices so that the user can easily control the combined A/V devices. The A/V devices are connected to other A/V devices via a network interface, thereby providing a single A/V network system.
As a part of this technology, the eXpandable Home Theater (XHT) specification, which is middleware for A/V home networking, has been developed recently. XHT technology is a digital-TV-oriented home network solution developed by Samsung Electronics Co., Ltd. The XHT specification has been adopted as a standard of the Consumer Electronics Association (CEA).
XHT technology controls multiple digital TVs as well as A/V devices connected to the digital TVs by use of IEEE 1394 cables which can stably transfer a plurality of high definition (HD) signals and Internet protocols. With XHT technology, a user can, for example, watch a digital broadcast in another room using a function for receiving the digital broadcast of the digital TV in the living room.
A memory card can act as a low-cost network interface unit (NIU) using XHT technology. Therefore, any changes to receiving systems, such as ground wave, satellite, and cable systems, can be easily performed, which reduces the economic burden of broadcast industrialists. In particular, XHT technology enables various kinds of portal services through the built-in browser of the digital TV.
Under this XHT environment, interactive data broadcast service of a digital TV is performed by a middleware included, for example, in a set-top box or a network interface unit (NIU) serving as the set-top box. The interactive-data broadcast has three standards in every broadcasting platform: the digital video broadcasting multimedia home platform (DVB-MHP) in Europe for satellite broadcasts, the open cable application platform (OCAP) in the U.S. for cable broadcasts, and the advanced common application platform (ACAP) in the U.S. for ground wave broadcasts.
FIG. 1 illustrates a graphical data communications system according to the related art.
The graphical-data communications system in the XHT network according to the related art includes a graphical-data-transmitting device 100, a graphical-data-receiving device 130, and a 1394 bus 125 that connects them.
The graphical-data-transmitting device 100 includes a graphical-control module 105, a control module 110, a Motion Pictures Expert Group (MPEG) processor 115, and a transmitting unit 120, and transmits broadcast contents transmitted from a head-end to a digital TV via the 1394 bus 125 of the XHT.
The graphical-control module 105 creates an image signal (hereinafter, referred to as “graphical data”) corresponding to a hypertext transfer protocol (HTTP) request (the request from the user for a certain page) conveyed from a web browser (not illustrated) of a graphical-data-receiving device 130 via the 1394 bus 125, and transmits the image signal to the graphical-data receiving unit 130 over the 1394 bus 125. The created graphical data is transmitted to a HTML-based page.
In more detail, the control module 110 calls a function for generation of graphical data according to the HTTP request conveyed from a web browser (not illustrated) of the graphical-data-receiving device 130, and transmits the graphical data to the graphical-control module 105. Then, the control module 110 transmits an A/V stream stored in the head-end (not illustrated) or in the corresponding device to the graphical-data-receiving device 130.
The transmitting unit 120 creates the isochronal stream for isochronal transmission of the A/V stream, and transmits the graphical data created by the graphical-control module 105 to the graphical-data-receiving device 130 via the 1394 bus 125.
The MPEG processor 115 processes general A/V streams.
The graphical-data-receiving device 130 includes a control module 135, a receiving unit 140, a MPEG decoder 145, a synthesizing unit 150, and a display unit 155, and displays an HTML page corresponding to the user's request based on the A/V stream and the graphical data conveyed from the graphical-data-transmitting device 100.
The control module 135 of the graphical-data-receiving device 130 transmits the HTTP request input by a user to the graphical-data-transmitting device 100, and transmits the A/V stream to the MPEG decoder 145 in order to decode the A/V stream transmitted from the graphical-data-transmitting device 100.
The synthesizing unit 150 synthesizes graphical data provided in response to the HTML and the A/V stream decoded in the MPEG decoder 145, and display unit 155 displays the synthesized graphical data on a screen.
The related art graphical-data-transmitting device 100 and the related art graphical-data-receiving device 130 including the above-described components have a web server and a web browser, based on which the transmission and reception of the graphical data were performed. The devices must perform a separate process for modifying the graphical data when a user interface (UI) is created or controlled internally like a middleware for the interactive service (e.g., the DVB-MHP, the OCAP, the ACAP), or when the HTML-based UI is not provided.
FIG. 2 illustrates a flow of graphical data transmission according to the related art.
The graphical data transmission in the XHT network according to the related art is performed between the related art graphical-data-transmitting device 100 and the related art graphical-data-receiving device 130 of FIG. 1.
First, the user selects an optional graphical-data-transmitting device 100 connected to the XHT network through the screen of the graphical-data-receiving device 130 (operation S100).
Verification of the graphical-data-transmitting device 100 is performed through a general method, and the optional graphical-data-transmitting device 100 is selected by the user through a remote controller or a predetermined inputting means.
When the optional graphical-data-transmitting device 100 is selected S100, the user (not illustrated) requests a specific page from the graphical-data-transmitting device 100 through a remote controller or a predetermined input means. Here, the request for the specific page is an HTTP request based on the web browser of the graphical-data-receiving device 130, and the corresponding request is performed by being transmitted to the graphical-data-transmitting device 100 (operation S110).
The graphical data is created by calling a function for generation of an image signal of the control module 110 in the graphic-control module 105 of the graphical-data-transmitting device 100 (operation S120). The created graphical data is a page in HTML format corresponding to the HTTP request from the user.
When the HTML-based graphical data created in the graphical-data-transmitting device 100 is generated in operation S120, predetermined A/V stream transmitted from the head-end or pre-stored in the corresponding device is transmitted with the HTML page to the graphical-data-receiving device 130 through the 1394 bus 125 based on the transmitting unit 120 (operation S130).
The graphical-data-receiving device 130 that received the HTML page and the A/V stream decodes the A/V stream (operation S140), and combines the decoded video stream and the HTML page (operation S150) to be displayed on screen (operation S160).